In a silver halide color photographic light-sensitive material, an organic compound termed color coupler is used to form a color image. Said silver halide color photographic light-sensitive material contains at least three kinds of silver halide emulsions being photosensitive to blue light, green light and red light, and contains at least three kinds of couplers each corresponding to the three primary colors of light. When said silver halide color photographic light-sensitive material is exposed to light and then processed in developing solution containing a color developing agent, it forms the three colors of yellow, magenta and cyan, which are produced by reaction of an oxidized color developer generated in response to the amount of exposure with three kinds of couplers. By blending pixels of these three colors, all colors in the visible spectrum can be produced.
In these color couplers, in cases where a carbon atom of the couplers reacting with the oxidized color developing agent (this carbon atom being called a coupling-positioned carbon atom) is not substituted by any substituent (active methylene), four silver atoms are theoretically required to form one molecule of dye. On the other hand, in cases where the coupling-positioned carbon atom is substituted by an anionic eliminating group, it is known that two silver atoms are required to form one molecule of dye. The former is termed a four-equivalent coupler, and the latter is termed a two-equivalent coupler. Said two-equivalent coupler generally exhibits high coupling reactivity and is used in many color photographic materials because smaller amount of silver halide is required to obtain the same density of dye, compared to the four-equivalent coupler.
Cited as eliminating groups of the two-equivalent coupler, are a halogen atom, an alkoxy group, a phenoxy group, an alkylthio group, a phenylthio group and a nitrogen-containing heterocyclic group, etc., and combined usage of the two-equivalent couplers containing various eliminating groups is employed in current color photographic light-sensitive materials. Specifically couplers in which the coupling-positioned carbon atom is substituted by a halogen atom, such as a chlorine atom and a bromine atom, etc., is not only useful as a final coupler but also useful as an intermediate to introduce an eliminating group other than the halogen atom to the coupling-positioned carbon atom of the coupler by nucleophilic substitution reaction. For this reason, in manufacturing photographic color couplers, the halogenation reaction process is considered to be very critical.
Various methods for introducing the halogen atom to the photographic color coupler and its intermediate are known. For example, as described in Japanese Patent Publication Open to Public Inspection (hereinafter referred to as JP-A) Nos. 60-55343, 61-57536, it is known that chlorine gas and sulfuryl chloride are reacted in a halogen type solvent. However, the above mentioned method exhibits problems such as, toxicity of the chlorine gas, sulfurous acid gas and hydrogen chloride gas generated in course of reaction being dispersed into the air, production of by-products caused by acidification in the course of the reaction, and corrosion of the reaction vessel.
With respect to a halagenation agent to overcome these problems, disclosed in JP-A 60-98434 is N-chlorosuccinimide as a chlorination agent for a photographic color coupler. In this case, it is possible to prevent the generation of the sulfurous acid gas and hydrogen chloride gas which is a problem in using sulfuryl chloride, etc., but there have been other problems such as the necessity to remove resultant succinimide after reaction and the high cost of N-chlorosuccinimide.
Further, dihalohydantoin has been recently disclosed for an use to synthesize the photographic color coupler and its intermediate in JP-A Nos., 7-304776, 8-301830, 8-310999, 9-59197 and 9-59250, etc. However, this agent is not sufficiently acceptable in reaction yield, side reaction and cost of the agent. Therefore, more improvement is sought.